The proposed research involves neural and behavioral studies of feeding in the marine mollusc Aplysia. It will concentrate on a neural analyses of the central arousal state that appears to control the intensity and latency of feeding. Studies will be done on (1) the basic neural circuits controlling feeding, (2) the mechanisms of persistence of the arousal state, with special reference to the role of serotonin and cyclic adenosine monophosphate and (3) the mechanisms of satiation of feeding behavior.